Effects of thyme, basil, and garlic oleoresins on the thermal resistance of Bacillus coagulans in tomato sauce

摘要

In this study, the thermal resistance of Bacillus coagulans in tomato sauce enriched with oleoresin was investigated. Thyme, basil, and garlic oleoresins were used at the minumum inhibitory concentrations of the target microorganism, B. coagulans, which were found as 1.25 ml/100 ml for the basil and garlic, and 2.5 ml/100 ml for the thyme oleroesin in the tomato sauce (pH:4.2, degrees Brix:10). Different temperatures between 80 and 105 degrees C were studied for determining the thermal resistance of microorganism. The D-90 values were determined as 6.28, 17.03, 13.52, and 14.79 min and the z values were found as 23.7, 22.7, 20.1, and 24.9 degrees C for the thyme, basil, garlic, and control (without oleoresin) groups, respectively. Sauce groups were also evaluated for the quality properties after production and also after 1 month of storage at +4 degrees C. The lycopene (230.1 mg/g) and degrees Brix (13.36%) values were found mostly in the thyme oleoresin group after storage. There was no significant difference between the color values of the garlic and control group. Practical applications Oleoresins provide an antimicrobial effect and the resistance of the microorganism was reduced, this way the lethal effect was ensured in a short-time interval. The current study demonstrated that oleoresins provided a 4 log reduction of B. coagulans vegetative cells in tomato sauce during 59.16 min for the control sauce, for thyme 25.12 min, 68.12 min for basil, and 54.08 min for garlic at 90 degrees C. The oleoresin of garlic may be preferred for the enrichment of tomato sauce.